docs: def get_asset_ddos():
      """Get DDO of all assets.
      ---
      tags:
        - ddo
      responses:
        200:
          description: successful action
      """
      args = []
      query = dict()
      args.append(query)
      assets_with_id = dao.get_all_listed_assets()
      assets_metadata = {a['id']: a for a in assets_with_id}
      for i in assets_metadata:
          _sanitize_record(i)
      return Response(json.dumps(assets_metadata, default=_my_converter), 200,
                      content_type='application/json')